Firefox OS was meant to be an affordable mobile operating system, and so far, Mozilla’s intention has succeeded. We suppose ‘free’ is affordable enough; it’s even cheaper than the ZTE Open we reported on yesterday. Of course, there are catches; it's more for development, and it's in alpha.

Thanks to an official Mozilla add-on, it’s possible to test out Firefox OS with apps from within the browser. Unsurprisingly, to test the OS you need to be running Firefox. Somehow, it works as an add-on for the browser. Compared to most add-ons, the 50MB download is rather hefty, but it's not much for developers.

Regardless, the concept is fairly neat, if not immediately user-friendly. Mozilla already has a fleshed-out page on their developer website, detailing the simulator. For the average user it’s not going to mean much when they’re presented with the OS Simulator, but it’s at least another way to test apps if they wish.

For Mozilla’s part, the concept might kick start some development. After all, not every operating system is free to develop for, and not every OS lets you test your work from within a web browser either.